1. Field of the Invention
The present invention relates to nano-biotechnology, and particularly to the synthesis of nanoparticles of metals and metal oxides using plant seeds extract, and to the use of these nanoparticles in treatment of sewage water and as antibacterial agents.
2. Description of the Related Art
Nano-biotechnology represents the intersection of nano-technology and biotechnology, which is an emerging field dedicated to the creation and utility of nanoscale structures. An important area of research and development in this field is the synthesis of nanoparticles. Metal nanoparticles are especially of great interest owing to their distinctive features, such as catalytic, optical, magnetic and electrical properties. Nanoparticles exhibit completely new or improved properties compared to the bulk materials, and these properties are derived from the variation in size, morphology and distribution of the particles. The biosynthesis of noble metal nanoparticles (e.g., silver and gold) has received considerable attention due to their wide application in consumer products, medicine, pharmaceutical and other biomedical products.
Various mechanical, chemical and biological methods have been employed to synthesize nanomaterials. Examples of mechanical processes for producing nanoparticles include mechanical attrition (e.g., ball milling), crushing of sponge iron powder, and thermal quenching. Examples of chemical processes for producing nanoparticles include precipitation techniques, sol-gel processes, and inverse-micelle methods. Chemical synthesis methods (such as sol-gel process, micelle, chemical precipitation, hydrothermal method, pyrolysis, chemical vapor deposition etc.), however, lead to the presence of some toxic chemical species adsorbed on the surface that may have adverse effects in medical applications. Some reactions require high temperature and/or high pressure for initiating the reaction, while other reactions require inert atmosphere protection, and/or require noxious H2S gas, toxic template and stabilizers. Thus, chemical methods used for synthesis and stabilization of nanoparticles lead to non-ecofriendly byproducts.
On the other hand, biological approaches using microorganisms and plants or plant's extracts for synthesis of metal nanoparticles have been suggested as viable alternatives to chemical methods. Several biological systems including bacteria, fungi and yeast have been used in the synthesis of nanoparticles. Synthesis of nanoparticles using microorganisms, however, involves an elaborate process of maintaining cell cultures, intracellular synthesis and multiple purification steps. In this regard, using “green” methods in the synthesis of metal nanoparticles has received attention as conventional chemical methods are expensive and require the use of hazardous chemical compounds and organic solvents.
Thus, the synthesis of nanoparticles of metals and metal oxides using plant seeds extract solving the aforementioned problems is desired.